Helmet



FIG. 1 is a front perspective view of a helmet showing my new design; the facemask shown in broken lines forms no part of the claimed design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a perspective view thereof, the facemask and padding shown in broken lines forms no part of the claimed design. 

The ornamental design for a helmet, as shown and described. 